Furnace



(No Model.)

G. P'. DENIS. PURNAGB.

No. 422,187. Patented Feb. 25, 1890l WITNESSESI l f 24 45,/ L Wgr lmmm/9% f/IW/f'y Mwe UNITED STATES NPATENT OEEIGE.

GEFFROY P. DENIS, CHESTER, PENNSYLVANIA.

FURNACE.

SPECIFICATION forming part of Letters Patent No. 422,187, dated February25, 1890. Application filed January Il, 1889i Serial No. 296,092. (Nomodel.)

To all whom it may concern:

Beit known that I, GEEEROY l?. DENIS, a citizen of the United States,residing at Chester, in the county of Delaware, and State ofPennsylvania, have invented certain new and useful Improvements inFurnaces, of which the following is aspeciflcation.

My invention relates to the class of appliances whichV are attached tofurnaces to arrest the unconsumed products of combustion in the smokestack and occasion their ret-urn to the grate, and also to suchappliances as are employed to lead fresh air to the grate to act as adraft.

The object of my invention is the construction of simple, efficient, andautomatic apparatus of the' character above indicated.

In the drawing I show in a perspective, partly sectional View, a furnaceprovided with my improvements.

A indicates the furnace and boilers of any preferred character, B thegrate bars, and C the chimney. 4

D-indicates a damper supported within the chimney and adapted whenclosed to completely seal its flue. Y The damper represented is of thesimplest type, and other forms may if desired be substituted in itsstead. E is a pipe or duct, the upper end of which is in communicationwith the flue of the chimney at a point below the damper and the lowerend of which leads to the grate. Intermediate of its length, the pipe isprovided with an enlargement e, in which rotates an exhaust fan F of anysuitable character, conveniently mounted upon a shaft f passing` throughthe pipe E at an elbow E thereof, supported upon a bracket EX attachedto the furnace, and at its outer end provided with a band Wheelf. Thepipe E is at a point between the chimney and the exhaust fan providedWith an air or oxygen inlet P. This inlet may be a simple orifice in thepipe, or a branch pipe may, as shown in the drawing, lead to it from amore or less remote source of air oroxygen supply. The pipe E as statedterminates at the grate, and preferably has discharge openings or outletpipes "e and e2 respectively above and below it. The upper outlet pipeis a section of pipe branching from the pipe E, and discharging into thefurnace at a point above the grate bars, preferably at an elevationsufficient to clear the fnel`upon the grate. In the drawing the lowerextremity of the pipe E is introduced into the furnace to constitute thelower outlet pipe e2. Both the upper and the lower outlet pipes may bebranched, turned, or extended, in any manner which will produce the bestresults.

In the drawing I have indicated in dotted lines an extension of thelower outlet pipe along the front of the grate, the extension embodyingtwo outlets for the contents of the pipe, one beneath each of theboilers with which the furnace is provided, so that the contents of thepipe will be consumed at points where the heat generated will be ofgreatest advantage. In practice I contemplate extending the lower outletpipe, placing it in a position just in front of the bridge wall, and,where a plurality of boilers is employed, locating the outletsthemselves one under each boiler.

In practice it may be found best to provide, at the points in the gratebars immediately over the outlets of the pipe e2, spaces between saidgrate bars of more than the normal Width, or openings may be formed inthe grate bar surface by entirely removing portions of the grate bars,so that there will be no accumulation of fuel abovelsaid outlets toprevent the ascent of the gases and smoke.

G G are a pair of cone pulleys of the ordinary type, mounted in abracket frame g, at the side of the furnace, and G is the band common toboth pulleys. y

II is a power shaft in any convenient manner connected to and driven bythe machinery operated by the steam generated in the boilers, upon whichshaft is mounted a pulley I-I, connected by a band h to the axle of oneof the cone pulleys G G, in the arrangement shown in the drawing thelower one. The location of the shaft H and pulley H is governed by thesurroundings of the furnace.

I is a band connecting the axle of the upper cone pulley to the bandwheel f. The power derived from the pulley H is therefore transmitted toand serves to drive the exhaust fan. To shift the belt GX of the conepulleys,

I employ a fork K, the prongs of which lie onefon each side of saidbelt, and connect the IOO shank of said fork to one arm of a bell cranklever L pivotally supported upon a bracket LX. To the other arm of saidbell crank lever is attached a rigid depending rod l the lower end ofwhich is attached to a rocking lever M pivotally mounted upon a bracketm so as to be free for a rising and falling movement. d is an armmounted upon one extremity of the axle of the damper D, to the free endof which arm is attached a rigid depending rod d the lower end of whichis in turn attached to the rocking lever M.

N is the weight arm of an automatic steam damper regulatoi',-adevicewell known to those familiar with the art to which this inventionappertains, and which I deem unnecessary to describe otherwise than bysaying that its base N is in communication with the interior of theboiler, and it is therefore subject to the pressure of the steam bywhich it is caused to rise and fall, and thereby through the connectingrods control the damper. The amount of pressure which will cause the armt0 rise may be predetermined and regulated by the set of the weight Nwith which said arm is provided. The outer end of the arm of theregulator is connected by a rigid rod n with the end of the rockinglever.

The operation is as follows: When the combustion is low and a smallpressure of steam is acting on the regulator NX the arm of the latterwill occupy a depressed position and the lever IWI will be tilted to aposition in which its outer end is much lower than its pivot. The damperD will therefore be closed and through the instrumentality of the bellcrank lever and fork the belt GX will have been caused to occupy aposition near the vright hand end of the pulleys, so that the speed ofrotation given to the band wheel f and consequently to the exhaust fanwill be augmented. Under these conditions the smoke gases and productsof combustion are stopped by the closed damper and by the action of theexhaust fan drawn from the chimney and caused to descend through thepipe E, the fan also serving through the inlet pipe P to suck air oroxygen, which mingles with its contents, into the pipe and becomesheated therein. The amount of air or oxygen which is drawn in willdepend upon the size of the inlet and the draft of the fan. The draftcreated by the fan is sufficiently powerful to prevent the escape ofsmoke, gases or products of combust-ion through the inlet. As stated,either atmospheric air, or oxygen of greater or less purity and drawnfrom a suitable reservoir, will enter the inlet. Vhen the heatedcommingled smoke, gases, products of combustion, and air or oxygen,reach the lower portion of the pipe E, more or less of the lighterelements among them will escape at the upper orifice or outlet, whilethe remainder will escape through the lower outlet and be dischargedbeneath the grate. The draft doors of vthe furnace are kept constantlyclosed because the contents of the pipe E act as both draft and feed tothe fire. lVhen under this treatment the heat ofthe fire increases, andthe steam has reached apredetermined pressure, the arm of the regulatorrises, and by so doing lifts the tilting arm M, which, through the rodld and armd opens the damper, and through the rod Z raises the outer armof the bell crank lever and causes the fork thereof to shift the conepulley belt GX to the left, with the result that the speed of rotationof the fan is reduced, but a portion of the contents of the chimney andalesser quantity of air fed to the grate, and the combustion inconsequence diminished. As the fire goes down, the steam pressuredecreases, thus again causing the closing of the damper, and increasingthe speed of the exhaust fan.

By the use of my invention the furnace is caused to consume its ownsmoke and gases. The combustion of theJ furnace is automaticallyregulated and maintained uniform, and the feeding of the contents of thepipe E to the furnace reduces the amount of coal otherwise necessary tobe fed to it. i

Having thus described my invention, I claim y l. In combination with afurnace and chimi ney, a pipe leading from the chimney to the lower partof the furnace and having outlets discharging respectively above andbelow the furnace grate, the exhaust fan, the cone pulleys connectedtherewith, the fork, the bell crank lever, the rocking lever connectedto said bell crank lever, the steam regulator connected to said rockinglever, and the power shaft, connected with the cone pulleys, sub-lstantially as set forth.

2. In combination with a furnace and chim ney, a pipe embodying an airinlet and leading from the chimney to the lower part of the furnace, thedamper, exhaust fan, means for operating said fan and said damper andcommon to both said devices, substantially as set forth. y

3. In combination with a furnace and chimney, a pipe leading from thechimney to the lower part of the furnace, a damper, an exhaust fan,mechanism for rotating the fan, mechanism for controlling the rotationof the fan, and an automatic steam regulator connected to the damper andto the mechanism for controlling the speed of the fan, substantially asset forth.

t. In combination withafurnace and chimney, a pipe leading from thechimney to a lower part of the furnace, an air inlet, a damper, anexhaust fan, and mechanism for causingthe associated operation of thedamper and fan, substantially as set forth.-

5. In combination with a furnace and chimney, a pipe leading from thechimney to the lower part of the furnace, the exhaust fan, the mechanismfor operating said fan, which mechanism includes a pair of cone pulleys,mechanism for shifting the belt of said pulleys, the damper, anautomatic steam regulater, and the rocking lever connected to the IOOIIO

steam regulator, and also connected to the damper and to the mechanismfor shifting thelbelt of the cone pulleys, substantially as set forth.

6. In combination with a furnaeeand chimney, a pipe leading from thechimney to the lower part of the furnace and having outlets whichdischarge respectively above and below' the grate, the exhaust fan, themechanism Afor operating said fan, which mechanism ineludesa pair ofcone pulleys, mechanism for shifting the belt of said pulleys, thedamper,

